1. Biostatistics and Methodology Unit Institut Paoli‐Calmettes Marseille France
2. Aix Marseille Univ, INSERM, IRD SESSTIM Marseille France
3. Biostatistics Unit Institut Claudius Regaud‐IUCT‐O Toulouse France
4. Laboratoires Pierre Fabre 3 ave Pierre Curie Toulouse France
5. Department of Statistics and Actuarial Science University of Waterloo Waterloo Ontario Canada